Audio system

ABSTRACT

In an audio system, a control device includes a setting part that sets automatic compensation of each of a plurality of input ports of the input device into either ON state or OFF state and an adjusting part that adjusts an analog gain of each of the plurality of input ports. The input device includes the plurality of input ports, each input port including an amplifier that controls a level of an analog signal input to the input port based on the analog gain adjusted by the adjusting part, an AD converter that converts the analog signal from the amplifier into a digital signal, a compensator that controls a level of the digital signal from the AD converter based on a digital gain of the input port, and a selector that selects one of the digital signal from the AD converter and the digital signal from the compensator. when the automatic compensation of an input port of the input device is set into the ON state from the OFF state by the setting part of the control device, the digital gain of the input port varies in accordance with the analog gain of the input port so that a value change in the analog gain of the input port by the adjusting part is compensated by a value change in the digital gain of the input channel.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to an audio system constructed byconnecting a plurality of devices to an audio network.

2. Description of the Related Art

A mixing system, which is constructed by connecting a plurality ofmixing devices in parallel to one input device to which an audio signalis input, is known in the art. The gain of the audio signal input to theinput device is adjusted through an adjustment part and the adjustedaudio signal is provided in parallel to all mixing devices connected tothe input device. One mixing device receives the amount by which thegain has been adjusted by the adjustment part of the input device andcorrects the level of the audio signal provided from the input devicebased on the received amount of adjustment so as to cancel the amount ofadjustment of gain in the input device. Accordingly, even when gainadjustment, which is not necessarily optimal for each individual mixingdevice, has been performed in the input device, the gain adjustment isautomatically canceled in the individual mixing device.

A digital mixer having an automatic gain compensation function is alsoknown in the art. The level of an analog signal input to an analog inputport in this digital mixer is adjusted through an amplifier whose analoggain is variable and the analog signal is then converted into a digitalsignal through an A/D converter. The digital signal from the input portis input to an input channel through an input patch and the level of thedigital signal is adjusted through an attenuator whose digital gain isvariable and acoustic characteristics thereof are then adjusted throughan equalizer, a compressor, a fader, or the like. Then, if the userchanges the analog gain of the input port in the case where automaticgain adjustment is set to “on”, the digital gain of the attenuator inthe input channel of the digital mixer is changed to cancel the changeof the analog gain so that the gain is automatically compensated.

A network-type audio system is also known in the art. This network-typeaudio system is constructed of an audio network including a plurality ofdevices connected in a loop such that loop transmission is possiblebetween the devices. Partial operations of the mixing system such as aninput operation, a mixing operation, and an output operation areassigned respectively to the devices of the network-type audio systemsuch that the devices constitute the single audio system as a whole. Inthe audio network, an audio signal can be transmitted in real time and acontrol signal can also be transmitted through the same cable.

RELATED ART REFERENCES

[Patent Reference 1] Japanese Patent No. 4052072

[Patent Reference 2] Japanese Patent Application Publication No.2007-43249

[Patent Reference 3] Japanese Patent Application Publication No.2007-295551

Here, it is assumed that the conventional network-type audio systemincludes an input device having input ports for performing inputoperations and a mixing device having input channels for performingmixing operations. If the user has changed the analog gain of the inputport in the case where the conventional automatic gain compensationfunction is applied to such a network-type audio system, then thedigital gain of the input channel of the mixing device is automaticallychanged so as to compensate the change of the analog gain. Meanwhile,when an instruction to adjust the analog gain has been issued from aconsole, the analog gain of the input device is adjusted according tothe instruction and the digital gain of the mixing device isautomatically adjusted. However, since an audio network is presentbetween the devices, the instruction is not simultaneously received byboth the input device and the mixing device, thereby causing a problemin that the timings to change gain at the two devices are different.

SUMMARY OF THE INVENTION

Therefore, it is an object of the invention to provide a network-typeaudio system which can perform automatic gain control without timingdeviation.

To achieve the above object, an audio system of the invention comprisesa control device and a plurality of devices being connected to an audionetwork, the plurality of devices including an input device and a mixingdevice, wherein the control device controls each of the plurality ofdevices directly or via the audio network according to manipulationperformed by an operator, the control device including a setting partthat sets automatic compensation of each of a plurality of input portsof the input device into either ON state or OFF state and an adjustingpart that adjusts an analog gain of each of the plurality of inputports, wherein the input device includes the plurality of input portsand a sender, each input port including an amplifier that controls alevel of an analog signal input to the input port based on the analoggain adjusted by the adjusting part, an AD converter that converts theanalog signal from the amplifier into a digital signal, a compensatorthat controls a level of the digital signal from the AD converter basedon a digital gain of the input port, and a selector that selects one ofthe digital signal from the AD converter and the digital signal from thecompensator, and the sender sending the digital signals selected by theselectors of the plurality of input ports via the audio network, whereinthe mixing device includes a receiver that receives the digital signalssent by the input device via the audio network, a plurality of inputchannels, each of which controls characteristics of each of the digitalsignals from the receiver, and a mix bus that mixes the digital signalsfrom the plurality of input channels, and wherein, (a) when theautomatic compensation of an input port of the input device is set intothe ON state from the OFF state by the setting part of the controldevice, the digital gain of the input port is set to a predeterminedvalue and the selector of the input port selects the digital signal fromthe compensator, (b) while the automatic compensation of an input portis in the ON state, the digital gain of the input port varies inaccordance with the analog gain of the input port so that a value changein the analog gain of the input port by the adjusting part iscompensated by a value change in the digital gain of the input channel,and, (c) when the automatic compensation of an input port of the inputdevice is set into the OFF state from the ON state by the setting part,the selector of the input port of the input device selects the digitalsignal from the AD converter.

Preferably, the control device comprises a console connected to theaudio network as one of the plurality of devices, the consol having acontrol panel which is provided thereon with a plurality of controlsoperable by an operator to control the audio system. Otherwise, thecontrol device comprises a personal computer connected to one of theplurality of devices, the personal computer running thereon a controlprogram for controlling the audio system.

In an expedient form, the audio system may be in combination withanother audio system connected to the audio network, wherein saidanother audio system comprises another control device having the sameconstruction as the control device of the audio system, and anothermixing device having the same construction as the mixing device of theaudio system, said another mixing device being controlled exclusively bysaid another control device, wherein the mixing device and the inputdevice of the audio system are controlled exclusively by the controldevice of the audio system, wherein said another mixing device includesa receiver that receives the digital signals sent by the input device ofthe audio system via the audio network, a plurality of input channels,each of which controls characteristics of each of the digital signalsfrom the receiver, and a mix bus that mixes the digital signals from theplurality of input channels, and wherein, while the automaticcompensation of an input port o the input device of the audio system isin the ON state, the receiver of said another mixing device receives thedigital signal having the level which is not changed by the analog gainof the input port adjusted by the adjusting part of the control deviceof the audio system.

Practically, the audio network is capable of transporting a plurality ofaudio signals and at least one control signal at the same time betweenthe plurality of devices connected to the audio network.

According to the invention, since a change in the analog gain of theinput port is compensated by the digital gain set in the compensatorprovided in the same input device, it is possible to achieve anautomatic gain compensation function of a network-type audio systemwhich can perform automatic gain compensation without timing deviation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an overall configuration of an audio system accordingto an embodiment of the invention.

FIG. 2 is a block diagram illustrating a hardware configuration of aconsole in the audio system of the invention.

FIG. 3 is a block diagram illustrating a hardware configuration of amixing engine in the audio system of the invention.

FIG. 4 is a block diagram illustrating a hardware configuration of an IOdevice in the audio system of the invention.

FIG. 5 is an equivalent diagram of connections of audio signals in theaudio system of the invention.

FIG. 6 illustrates flow of signal processing in the audio system of theinvention.

FIG. 7 illustrates details of a transmission path of an audio signalfrom input of the audio signal to an NIO in an IO device in the audiosystem of the invention.

FIG. 8 illustrates details of a transmission path of an audio signalfrom input of the audio signal to a patch in a mixing engine in theaudio system of the invention.

FIG. 9 illustrates details of a transmission path of an audio signalfrom an NIO or an AIO to mix buses in the mixing engine in the audiosystem of the invention.

FIG. 10 is a flow chart of an on/off manipulation process of automaticcompensation in the audio system of the invention.

FIG. 11 is a flow chart of an analog gain change process in the audiosystem of the invention.

FIG. 12 illustrates an overall configuration of an audio systemaccording to another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an overall configuration of an audio system accordingto an embodiment of the invention.

The audio system 1 shown in FIG. 1 is constructed of an audio network 2,to which devices such as a console (C) 1-1, a mixing engine (E) 1-2, anIO device 1-3 (IO1), an IO device 1-4 (IO2), and an IO device 1-5 (IO3)are connected in a ring, and a ring-shaped transmission path forcirculating frames of audio signals is formed on the audio network 2.The devices connected to the audio network 2 are connected to each otherthrough a physical connection cable. Only one of the devices connectedto the audio network 2 is a master device and the other devices areslaves. The master device transmits a frame to the ring-shapedtransmission path and the transmitted frame circulates in thetransmission path, returning to the master node. The frame includesstorage regions for a plurality of channels, a channel of apredetermined band is allocated to each of the plurality of devicesconnected to the audio network 2, and each device can transmit an audiosignal to the audio network 2 using the allocated channel. When a devicereceives an audio signal transmitted from a different device, the devicereceives the audio signal from a channel allocated to the differentdevice. The frame also includes a storage region for a control signaland thus any device can transmit a control signal to any other devicewhile transmitting an audio signal in the audio network 2. Various typesof remote control described later are all performed using communicationof this control signal. Namely, the audio network 2 is capable oftransporting a plurality of audio signals and at least one controlsignal at the same time between the plurality of devices connected tothe audio network 2.

When an analog audio signal is input to an input port of a deviceconnected to the audio network 2, the audio signal input to the inputport is received by the mixing engine 1-2 through the audio network 2.The mixing engine 1-2 mixes audio signals after adjusting level orfrequency characteristics of the audio signals and outputs a (mixed)audio signal produced by mixing the audio signals to a device includingan output port through the audio network 2. A device which has receivedthe mixed signal emits the mixed signal through a speaker or the likeafter amplification. The operator can allocate an input port of eachdevice to an input channel of the mixing engine 1-2 or can adjustacoustic characteristics of the input channel to a state, in which aplayed performance is heard optimally, by manipulating a variety ofpanel controls provided on the console 1-1. The operator can also set anon/off state of automatic compensation described later for each port.The audio system 1, which is a mixing system, is constructed of theaudio network 2 to which devices such as the console 1-1, the mixingengine 1-2, and the IO devices IO1 to IO3 are connected in a ring asdescribed above. The console 1-1 may function as a control device ofanother device and may be connected to any device instead of beingconnected to the ring-shaped audio network 2.

FIG. 2 is a block diagram illustrating a hardware configuration of theconsole 1-1. In the console 1-1 shown in FIG. 2, a Central ProcessingUnit (CPU) 10 executes an Operating System (OS), which is a managementprogram, and controls the overall operation of the console 1-1 throughthe OS. The console 1-1 includes a Read Only Memory/Random Access Memory(ROM/RAM) 11 which stores an operation program for the console executedby the CPU 10 and also stores a variety of data and work area data ofthe CPU 10. A panel display 12 includes a display device such as an LCDand displays a variety of screens such as those for setting a variety ofparameters. The panel controls 13 are controls such as faders, knobs,and switches provided on a panel of the console 1-1 and can be operatedto change values or on/off states of parameters of the console 1-1, themixing engine 1-2, or the IO devices. The electric faders 14 are each afader for adjusting the level or the like of an audio signal of an inputchannel or an output channel of the console 1-1 and can manually orelectrically perform level adjustment. The AIO 15 is an input/outputunit for audio signals and includes a plurality of analog input ports, aplurality of analog output ports, and a plurality of bidirectionaldigital input/output ports. Each of the analog input ports receives andconverts an analog audio signal received from the outside into a digital(input) audio signal and sends the digital audio signal to an audio bus17. Each of the analog output ports receives and converts a digital(output) audio signal from the audio bus 17 into an analog audio signaland outputs the analog audio signal. Each of the digital input/outputports receives a digital (input) audio signal from the outside and sendsthe digital (input) audio signal to the audio bus 17 and also outputs adigital (output) audio signal received from the audio bus 17. An NIO 16is a communication interface for connection to the audio network 2 toperform communication. The NIO 16 provides a plurality of (output) audiosignals received from the audio network 2 to the analog input ports orthe digital input/output ports of the AIO 15 through the audio bus 17and transmits a plurality of (input) audio signals provided from theanalog input ports or the digital input/output ports of the AIO 15 tothe audio network 2 through the audio bus 17. Components of the console1-1 exchange data with each other through a CPU bus 18 including addressand data buses and control buses. In short, the console 1-1 is a controldevice connected to the audio network 2 as one of the plurality ofdevices, the consol 1-1 having a control panel which is provided thereonwith a plurality of controls operable by an operator to control theaudio system 1.

FIG. 3 is a block diagram illustrating a hardware configuration of themixing engine 1-2 which functions as a mixing device. In the mixingengine 1-2 shown in FIG. 3, a CPU 20 controls the overall operation ofthe mixing engine 1-2 through an OS. The mixing engine 1-2 includes aROM/RAM 21 which stores an operation program for the mixing engineexecuted by the CPU 20 and also stores a variety of data and work areadata of the CPU 20. An easy UI 22 is a user interface such as a dial orbutton for easily performing setting of the mixing engine 1-2. An AIO 23has the same configuration as the AIO 15 described above and sends aplurality of (input) audio signals input from the outside to the audiobus 26 and also outputs a plurality of (output) audio signals receivedfrom the audio bus 26. A Digital Signal Processor (DSP) 24 is a signalprocessing unit that performs acoustic characteristics controlprocessing and mixing processing according to parameters on a pluralityof (input) audio signals which are provided from the AIO 23 or an NIO 25through an audio bus 26 and that provides a plurality of processed(output) audio signals to the AIO 23 or the NIO 25 through the audiobus. The NIO 25 is a communication interface for connection to the audionetwork 2 to perform communication. The NIO 25 sends a plurality of(input) audio signals received from the audio network 2 to the audio bus26 and transmits a plurality of (output) audio signals received from theaudio bus 26 to the audio network 2. Components of the mixing engine 1-2exchange data with each other through a CPU bus 27 including address,data, and control buses.

FIG. 4 is a block diagram illustrating a hardware configuration of theIO device 101 which is an input device and which is representativelyillustrated since the IO devices IO1 to IO3 have the same configuration.In the IO device IO1 shown in FIG. 4, a CPU 30 controls the overalloperation of the IO device IO1 through an OS. The IO device IO1 includesa ROM/RAM 31 which stores an operation program for the IO deviceexecuted by the CPU 30 and also stores a variety of data and work areadata of the CPU 30. An easy UI 32 is a user interface such as a dial orbutton for easily performing setting of the IO device IO1. An AIO 33 isthe same audio signal input/output unit as the AIO 15 described aboveand an NIO 34 is the same communication interface as the NIO 16described above. Components of the IO device IO1 exchange data with eachother through a CPU bus 36 including address, data, and control buses.

FIG. 5 is an equivalent diagram of connections of audio signals in theaudio network 2. In FIG. 5, the audio network 2 is illustratedequivalently by buses corresponding to a plurality of channels allocatedto devices. In the audio network, since each channel is allocated toonly one device and is not simultaneously allocated to another device,an audio signal that a device has transmitted through a channel can bereceived by any device connected to the network. In FIG. 5, “ch-E”denotes a channel allocated to the mixing engine 1-2, “ch-C” denotes achannel allocated to the console 1-1, “ch-1” denotes a channel allocatedto the IO device IO1, and “ch-2” denotes a channel allocated to the IOdevice IO2. The console 1-1 sends an (input) audio signal, which hasbeen input to an analog input port or a digital input/output port of theconsole 1-1, to the channel ch-C. The IO device IO1 sends an (input)audio signal, which has been input to an analog input port or a digitalinput/output port of the IO device IO1, to the channel ch-1. The IOdevice IO2 sends an (input) audio signal, which has been input to ananalog input port or a digital input/output port of the IO device IO2,to the channel ch-2. The mixing engine 1-2 receives a plurality of(input) audio signals from the channels ch-C, ch-1, and ch-2 (whilereceiving an audio signal from the AIO 23 of the mixing engine 1-2) andperforms acoustic characteristics control processing and mixingprocessing on the received audio signals and then sends a plurality ofprocessed (output) audio signals to the channel ch-E (while outputtingthe processed audio signals through the AIO 23). The console C receivesa plurality of (output) audio signals from the channel ch-E and outputsthe audio signals to an external audio device through the analog outputports or the digital input/output ports of the console C. Each of the IOdevices IO1 and IO3 also receives a mixed signal from the channel ch-Eand outputs the signal to an audio device or a speaker connected to theIO device.

FIG. 6 illustrates flow of signal processing associated with the audiosystem 1.

As shown in FIG. 6, among a plurality of analog or digital input portsAi(C) included in the AIO 15 of the console 1-1, a plurality of analogor digital input ports Ai(#1) included in the AIO 33 of the IO device101, a plurality of analog or digital input ports Ai(#2) included in theAIO of the IO device IO2, a plurality of (input) audio signals from aplurality of desired input ports connected to patches Pca, Pa1, and Pa2is sent to the audio network 2. The mixing engine 1-2 receives aplurality of desired (input) audio signals among the audio signalsreceived from the audio network 2 and the received audio signals areinput to an input patch 41. A plurality of (input) audio signals fromanalog or digital input ports Ai (lo) 40 included in the AIO 23 of themixing engine 1-2 are also input to the input patch 41. In the inputpatch 41, one desired input of the plurality of inputs to the inputpatch 41 is patched (connected) to each input channel of an inputchannel portion 42 and an (input) audio signal from the patched input isprovided to the input channel. Each input channel of the input channelportion 42 includes an attenuator, an equalizer, and a compressor foradjusting acoustic characteristics. An audio signal of each inputchannel, whose acoustic characteristics have been adjusted, is sent tomix buses 43 after the send level of thereof at each bus is adjustedthrough a level adjuster. Each of the m mix buses 43 mixes one or moredigital signals, which have been selectively input from input channels.The m mix buses 43 then output a plurality of mixed signals to an outputchannel portion 44.

Each output channel of the output channel portion 44 also includes anequalizer, a compressor, and the like for adjusting acousticcharacteristics and performs frequency balancing or level adjustment andadjusts the sending level of an audio signal to the output patch 45. Inthe output patch 45, a desired input among a plurality of inputs fromthe plurality of output channels of the output channel portion 44 isselectively patched to each of a plurality of outputs of the outputpatch. The plurality of outputs are connected to a plurality oftransmission ports, which send a plurality of audio signals to thechannel ch-E of the audio network 2, and to a plurality of analog ordigital output ports Ao(lo) 46 included in the AIO 23 of the mixingengine 1-2. That is, (output) audio signals from the patched channelsare provided to the plurality of output ports Ao(lo) 46 and theplurality of transmission ports. The plurality of output ports Ao(lo) 46provides the plurality of received (output) audio signals to an externalaudio device and the plurality of transmission ports sends the pluralityof received (output) audio signals to the channel ch-E of the audionetwork 2.

In the console 1-1, the IO device IO1, and the IO device IO3, aplurality of (output) audio signals are received from the outputchannels of the mixing engine 1-2 through the audio network and are theninput to patches Pcb, Pb1, and Pb3. In the patches Pcb, Pb1, and Pb3, aplurality of (output) audio signals produced through mixing of theoutput channels are selectively patched to a plurality of analog ordigital output ports Ao(C), Ao(#1), and Ao(#3) and are then output fromthe plurality of output ports Ao(C), Ao(#1), and Ao(#3) to an externalaudio device.

On the console 1-1, the user can directly or remotely control patchingof the patches Pca, Pa1, and Pa2 and the input patch 41 to set patchingfrom desired input ports Ai(C), Ai(#1), and Ai(#2) of the input devices1-1, 1-3, and 1-4 to desired input channels of the mixing engine 1-2,and can also directly or remotely control patching of the output patch45 and the patches Pcb, Pb1, and Pb3 to set patching from desired outputchannels of the mixing engine 1-2 to desired output ports Ao(C), Ao(#1),and Ao(#3) of the output devices 1-1, 1-3, and 1-5 by manipulating thepanel display or the panel controls on the console 1-1.

FIG. 7 illustrates a detailed configuration of a transmission path of anaudio signal from input of the audio signal to the NIO 34 in each of theIO devices IO1 to IO3.

As shown in FIG. 7, an analog audio signal is input to an analog inputport i of the IO device and then the IO device converts the analog audiosignal into a digital (input) audio signal and outputs the digital(input) audio signal. Here, the IO device includes a plurality of analoginput ports and each of a plurality of (input) audio signals from theplurality of ports is transmitted to a desired transmission port of theNIO 34, which has been selectively patched in the patch Pa, using onechannel of an audio bus 35. The analog input port i includes anamplifier 33a, an AD converter (ADC) 33b, a gain adjuster 33c, acompensator 33d, and a switch 33e. The amplifier 33a analog-amplifies ananalog (input) audio signal received from the outside by a specifiedanalog gain. The gain adjuster 33c specifies the analog gain of theamplifier 33a. The ADC 33b converts an analog audio signal output fromthe amplifier 33a into a digital audio signal. The compensator 33ddigital-amplifies a digital audio signal from the ADC 33b by a specifieddigital gain and outputs the amplified audio signal. The switch 33eselects and outputs one of the digital audio signal from the ADC 33b andthe digital audio signal from the compensator 33d. The bit width of theaudio signal output by the ADC 33b is 24 bits and the bit width of theaudio signal for transmission through the audio network is 32 bits. Ahead margin of 4 bits is secured among the 32 bits and the gain of thecompensator 33d can amplify an audio signal up to +24 dB. The changerange of the gain of the compensator 33d is, for example, −96 dB to +24dB. When a gain exceeding the change range is specified, the gain of thecompensator 33d is set to a value within the range closest to thespecified gain. The switch 33e is switched such that an operatingcontact a is connected to a fixed contact c when automatic compensationof the analog input port is turned on and is connected to a fixedcontact b when automatic compensation is turned off.

The operation of the analog input port i will now be described withreference to FIG. 10 which is a flow chart of an on/off manipulationprocess of automatic compensation and FIG. 11 which is a flow chart ofan automatic compensation process.

When on/off manipulation for automatic compensation of an analog inputport i corresponding to an input port x of the device IO1 or IO2 hasbeen performed on the panel of the console 1-1, the console 1-1transmits a control signal indicating the on/off manipulation to the IOdevice IO1 or IO2. In the IO device IO1 or IO2, which has received thecontrol signal, the on/off manipulation procedure of automaticcompensation shown in FIG. 10 is activated, and a flag ACS indicatingthe state of automatic compensation of the analog input port i isreversed at step S10. Then, whether the reversed flag ACS indicates anon or off state is determined at step S11. Here, when it is determinedthat the flag ACS indicates an on state, the procedure proceeds to stepS13 to set the digital gain of the compensator 33d of the analog inputport i to 0 dB. In addition, at step S14, the switch 33e is switched tothe compensator 33d at the fixed contact c. In this case, a digitalsignal, which has the same level as before automatic compensation isswitched to on, is output from the switch 33e since the digital gain ofthe compensator 33d is set to 0 dB.

When it is determined that the flag ACS indicates an off state, theprocedure proceeds to step S12 to switch the switch 33e of the analoginput port i to the ADC 33b at the fixed contact b.

When the process of step S12 or S14 is terminated, the on/offmanipulation procedure of automatic compensation is terminated. Theconsole 1-1 performs the on/off manipulation procedure shown in FIG. 10when on/off manipulation of automatic compensation of an analog inputport i corresponding to an input port x of the console 1-1 has beenperformed on the panel of the console 1-1.

When a manipulation to change the analog gain (parameter) of the gainadjuster 33c of the analog input port i corresponding to the input portx of the IO device IO1 or IO2 has been performed on the console 1-1, theconsole 1-1 transmits a control signal indicating the changemanipulation to the IO device IO1 or IO2. In the IO device IO1 or IO2,which has received the control signal, the analog gain change procedureshown in FIG. 11 is activated and the analog gain (parameter) of theamplifier 33a of the analog input port i is changed according to amanipulation value associated with the manipulation or according to theamount of the manipulation at step S20. Then, whether the flag ACS ofthe input port indicates an on or off state is determined at step S21.Here, when it is determined that the flag ACS indicates an on state, theprocedure proceeds to step S22 to change the digital gain of thecompensator 33d of the analog input port i by an inverse of the amountby which the analog gain has been changed at step S20. Accordingly, thecompensator 33d outputs an audio signal having a level from which thechange of the analog gain by the gain adjuster 33c has been canceled(i.e., outputs an audio signal having the same level as the original).That is, even when the operator has manipulated the console 1-1 so thatthe analog gain of an amplifier 33a of an analog input port i haschanged, the compensator 33d compensates the change of the analog gain,if a flag ACS of the analog input port i is on, and thus the analoginput port i outputs an (input) audio signal having the same level asbefore the manipulation.

On the other hand, when the flag ACS is off, the process of step S22 isnot performed and the change of the analog gain by the operator isdirectly reflected in an (input) audio signal output from the analoginput port i. Since on/off of automatic compensation (ACS flag) is setfor each analog input port, a common ACS flag is used for a plurality ofinput channels when the same analog input port has been patched to theplurality of input channels. In addition, on/off of automaticcompensation is common to all input channels connected to the sameanalog input port since on/off of automatic compensation is set for eachanalog input port. The analog gain change procedure shown in FIG. 11 isperformed by the console 1-1 when a manipulation to change the analoggain of the analog input port i corresponding to the input port x of theconsole 1-1 has been performed on the panel of the console 1-1.

Namely, according to the invention, (a) when the automatic compensationof an input port i of the input device (namely, IO1 or IO2) is set intothe ON state from the OFF state by the setting part of the controldevice (namely, console 1-1), the digital gain of the input port i isset to a predetermined value and the selector 33e of the input port iselects the digital signal from the compensator 33d, (b) while theautomatic compensation of an input port i is in the ON state, thedigital gain of the input port i varies in accordance with the analoggain of the input port i so that a value change in the analog gain ofthe input port i by the adjusting part 33c is compensated by a valuechange in the digital gain of the input channel, and, (c) when theautomatic compensation of an input port i of the input device is setinto the OFF state from the ON state by the setting part, the selector33e of the input port i of the input device selects the digital signalfrom the AD converter 33b.

FIG. 8 illustrates a detailed configuration of a transmission path of anaudio signal from input of the audio signal to the patch in the mixingengine 1-2.

As shown in FIG. 8, an analog audio signal is input to an analog inputport j of the mixing engine 1-2 and then the mixing engine 1-2 convertsthe analog audio signal into a digital (input) audio signal and outputsthe digital (input) audio signal. Here, the mixing engine 1-2 includes aplurality of analog input ports and each of a plurality of (input) audiosignals from the plurality of ports is transmitted to a desired channelof the input channel portion 42, which has been selectively patched inthe input patch 41, using one channel of the audio bus 26. The analoginput port j has the same configuration as the analog input port i ofFIG. 7, and blocks 40a to 40e of the analog input port j operate in thesame manner as the corresponding blocks 33a to 33e. In the procedures ofFIGS. 10 and 11, the input port x corresponds to the analog input port jand, even when the operator has changed the analog gain of the amplifier40a remotely from the console 1-1, the change is compensates by thedigital gain of the compensator 40d and the analog input port j outputsan (input) digital audio signal having the same level as before thechange of the analog gain if the ACS flag of the analog input port j ison.

In addition, although not illustrated, a detailed configuration of thetransmission path of an audio signal from input of the audio signal tothe NIO 16 in the console 1-1 is the same as that of the IO devicedescribed above and operation thereof is also the same as that of the IOdevice described above.

FIG. 9 illustrates a detailed configuration of a transmission path of anaudio signal from the NIO 25 or the AIO 23 to the mix buses 43 in themixing engine 1-2.

A plurality of (input) digital audio signals acquired from the audionetwork 2 through the NIO 25 or a plurality of (input) digital audiosignals input to the AIO 23 are directly input to the input patch 41. Onthe other hand, each of a plurality of (input) analog audio signalsinput to the AIO 23 is input to the input patch 41 after being convertedinto a digital (input) audio signal at the analog input port j shown inFIG. 8. In the input patch 41, one desired input among such a pluralityof inputs to the input patch 41 can be selectively patched (connected)to each input channel k of the input channel portion 42. The inputchannel k includes an attenuator (ATT) 42a, an equalizer (EQ) 42b, acompressor (Comp) 42c, and a level adjuster 42d. The attenuator 42aadjusts the level of a digital (input) audio signal based on anattenuator parameter. The equalizer 42b adjusts frequencycharacteristics of the same audio signal based on an equalizerparameter. The compressor 42c dynamically controls the level of the sameaudio signal based on a compressor parameter. The level adjuster 42dcontrols the send level of the audio signal for sending to each of themix buses 43 based on a send parameter corresponding to the mix bus. Theinput channel k adjusts characteristics of the audio signal throughthese components. Here, the attenuator parameter of the attenuator 42ais a parameter for adjusting the level of an audio signal input to theinput channel k to a level suitable for signal processing of theequalizer 42b or the compressor 42c, independently of digital gain oranalog gain of the analog input port i or j. Each of the mix buses 43receives audio signals, the levels of which have been controlled forinput to the mix bus 43, from a plurality of input channels and mixesthe received audio signals and outputs the mixed audio signal. In thecase of an input channel k patched to an analog input port i or j whoseautomatic compensation (ACS) is off, the level of an audio signal inputto an attenuator 42a of the analog input port i or j changes, if theanalog gain of the analog input port i or j changes, and therefore theoperator should readjust the attenuator parameter. On the other hand, inthe case of an input channel k patched to an analog input port i or jwhose automatic compensation (ACS) is on, the level of an audio signalinput to an attenuator 42a of the analog input port i or j does notchange due to automatic compensation by the compensator 33d or 40d, evenif the analog gain of the analog input port i or j changes, and thus theoperator does not have to readjust the attenuator parameter.

FIG. 12 illustrates an overall configuration of an audio systemaccording to another embodiment of the invention.

The audio system 5 of FIG. 12 includes a subsystem Sa and a subsystem Sbwhich are connected to an audio network 6. The subsystem Sa includes aconsole Ca, a mixing engine Ea, and four IO devices IOa1, IOa2, IOa3,and IOa4 which are connected to the audio network 6. The subsystem Sbincludes a console Cb, a mixing engine Eb, and an IO device IOb1 whichare connected to the audio network 6.

One of the nine devices connected to the audio network 6 is a masternode. The master device regularly transmits a transmission frame tocirculate through the audio network and also allocates a transmissionchannel to each of the nine devices. In this network, the subsystem Saand the subsystem Sb can share (input) audio signals since an audiosignal written to a transmission frame transmitted by one of the ninedevices can be received by other devices. That is, the mixing engine Ebof the subsystem Sb can receive (input) audio signals that the IOdevices IOa1, IOa2, IOa3, and IOa4 have transmitted to the audio network6 and the mixing engine Ea of the subsystem Sa can receive (input) audiosignals that the IO device IOb1 has transmitted to the audio network 6.

In the subsystem Sa, the console Ca serves as a control device of thesubsystem Sa and remotely controls the mixing engine Ea and the IOdevices IOa1, IOa2, IOa3, and IOa4. In the subsystem Sb, the console Cbserves as a control device of the subsystem Sb and remotely controls themixing engine Eb and the IO device IOb1. The devices of the subsystem Sbcannot be remotely controlled by the console Ca since the devices arenot under management by the subsystem Sa and the device of the subsystemSa cannot be remotely controlled by the console Cb since the device isout of the range of management by the subsystem Sb.

Here, let us consider the case where the mixing engine Eb in thesubsystem Sb extracts (input) audio signals, which the IO device IOa2 ofthe subsystem Sa has received through an analog input port i and hasthen transmitted to the audio network 6, and patches the extracted audiosignals to one input channel k and then performs a mixing process on theaudio signals. Here, the analog input port i is under control of theconsole Ca and the analog gain of the analog input port i is freelychanged through panel manipulation by the operator of the subsystem Sa.In the conventional technology (which corresponds to when automaticcompensation of the analog input port i of this embodiment is off),since the level of the (input) audio signal of the input channel k ofthe subsystem Sb changes, the operator of the subsystem Sb shouldreadjust an attenuator parameter of the input channel k which hasalready been adjusted, thereby complicating the manipulation process. Inthe invention, by allowing the operator of the subsystem Sb to have theoperator of the subsystem Sa turn on automatic compensation of theanalog input port i which shares (input) audio signals, the level of an(input) audio signal input to the input channel k is not changed evenwhen the analog gain of the analog input port i has changed and thus theoperator of the subsystem Sb does not have to readjust the attenuatorparameter.

As described above, audio system Sa is in combination with another audiosystem Sb connected to the audio network 6. The audio system Sbcomprises another control device Cb having the same construction as thecontrol device Ca of the audio system Sa, and another mixing device Ebhaving the same construction as the mixing device Ea of the audio systemSa, the mixing device Eb being controlled exclusively by the controldevice Cb. The mixing device Ea and the input device IOa of the audiosystem Sa are controlled exclusively by the control device Ca of theaudio system Sa. The mixing device Eb includes a receiver that receivesthe digital signals sent by the input device IOa of the audio system Savia the audio network 6, a plurality of input channels, each of whichcontrols characteristics of each of the digital signals from thereceiver, and a mix bus that mixes the digital signals from theplurality of input channels. While the automatic compensation of aninput port o the input device IOa of the audio system Sa is in the ONstate, the receiver of the mixing device Eb receives the digital signalhaving the level which is not changed by the analog gain of the inputport adjusted by the adjusting part of the control device Ca of theaudio system Sa.

In the audio device of the invention described above, if the analog gainof an input port, to which an analog audio signal is input, in an inputdevice has been changed by a console, a digital gain set in acompensator of the input port compensates a change in the analog gain.The compensator adjusts the digital gain of a digital signal into whichthe input analog signal has been converted and outputs the resultingdigital signal from the input port when the automatic gain compensationis on. Accordingly, it is possible to achieve an automatic gaincompensation function of a network-type audio system which can performautomatic gain compensation without timing deviation or time lag.

In addition, although a plurality of devices are connected in a ring tothe audio network 2, the plurality of devices may also be connected in adifferent form, for example, in a cascade. Further, although theconsoles C, Ca, and Cb operate as control devices in the embodiments ofthe invention, the control devices are not limited to the consoles. Forexample, the console of FIG. 2, the mixing engine of FIG. 3, and the IOdevice of FIG. 4 may be provided with an interface for connection to anexternal personal computer (PC), a program for controlling the audiosystem may be activated through an operating system of the PC connectedto the interface, and the activated program may operate as a controldevice of the audio system. Namely, the personal computer serves as thecontrol device connected to one of the plurality of devices, thepersonal computer running thereon a control program for controlling theaudio system.

What is claimed is:
 1. An audio system comprising a control device and aplurality of devices being connected to an audio network, the pluralityof devices including an input device and a mixing device, wherein thecontrol device controls each of the plurality of devices directly or viathe audio network according to manipulation performed by an operator,the control device including a setting part that sets automaticcompensation of each of a plurality of input ports of the input deviceinto either ON state or OFF state and an adjusting part that adjusts ananalog gain of each of the plurality of input ports, wherein the inputdevice includes the plurality of input ports and a sender, each inputport including an amplifier that controls a level of an analog signalinput to the input port based on the analog gain adjusted by theadjusting part and that outputs an analog signal, an AD converter thatconverts the analog signal output from the amplifier into a digitalsignal from the AD converter, a compensator that controls a level of thedigital signal from the AD converter based on a digital gain of theinput port and that outputs a digital signal, and a selector thatselects one of the digital signal from the AD converter and the digitalsignal output from the compensator, and the sender sending the digitalsignals selected by the selectors of the plurality of input ports viathe audio network, wherein the mixing device includes a receiver thatreceives the digital signals sent by the input device via the audionetwork, a plurality of input channels, each of which controlscharacteristics of each one of the digital signals from received by thereceiver, and a mix bus that mixes the digital signals from whosecharacteristics are controlled by the plurality of input channels, andwherein, (a) when the automatic compensation of an input port of theinput device is set into the ON state from the OFF state by the settingpart of the control device, the digital gain of the input port is set toa predetermined value and the selector of the input port selects thedigital signal output from the compensator, (b) while the automaticcompensation of an input port is in the ON state, the digital gain ofthe input port varies in accordance with the analog gain of the inputport so that a value change in the analog gain of the input port by theadjusting part is compensated by a value change in the digital gain ofthe input channel port, and, (c) when the automatic compensation of aninput port of the input device is set into the OFF state from the ONstate by the setting part, the selector of the input port of the inputdevice selects the digital signal from the AD converter.
 2. The audiosystem according to claim 1, wherein the control device comprises aconsole connected to the audio network as one of the plurality ofdevices, the consol console having a control panel which is providedthereon with a plurality of controls operable by an operator to controlthe audio system.
 3. The audio system according to claim 1, wherein thecontrol device comprises a personal computer connected to one of theplurality of devices, the personal computer running thereon a controlprogram for controlling the audio system.
 4. The audio system accordingto claim 1, in combination with another audio system connected to theaudio network, wherein said another audio system comprises anothercontrol device having the same construction as the control device of theaudio system, and another mixing device having the same construction asthe mixing device of the audio system, said another mixing device beingcontrolled exclusively by said another control device, wherein themixing device and the input device of the audio system are controlledexclusively by the control device of the audio system, wherein saidanother mixing device includes a another receiver that receives thedigital signals sent by the input device of the audio system via theaudio network, a another plurality of input channels, each of whichcontrols characteristics of each one of the digital signals from theanother receiver, and a another mix bus that mixes the digital signalsfrom the another plurality of input channels, and wherein, while theautomatic compensation of an input port o of the input device of theaudio system is in the ON state, the another receiver of said anothermixing device receives the a digital signal having the a level which isnot changed by the analog gain of the input port adjusted by theadjusting part of the control device of the audio system.
 5. The audiosystem according to claim 1, wherein the audio network is capable oftransporting a plurality of audio signals and at least one controlsignal at the same time between the plurality of devices connected tothe audio network.
 6. An apparatus comprising: an audio input port forreceiving an input analog audio signal, the audio input port comprising:an analog-amplifier for controlling a level of the input analog audiosignal based on an analog gain parameter to output an output analogaudio signal; an AD converter for converting the output analog audiosignal into an input digital audio signal; a digital-amplifier forcontrolling a level of the input digital audio signal based on a digitalgain parameter to output an output digital audio signal; and a switchfor selecting one of a first switch contact for outputting the outputdigital audio signal from the digital-amplifier and a second switchcontact for outputting the input digital audio signal from the ADconverter, wherein, (a) when an on/off state of gain compensation of theaudio input port is set into an ON state from an OFF state by theapparatus, the digital-amplifier sets the digital gain parameter to apredetermined value and the switch selects the first switch contact foroutputting the output digital audio signal from the digital-amplifier,(b) while the on/off state of the gain compensation of the audio inputport is in the ON state, the digital-amplifier adjusts the digital gainparameter inversely to a direction of a value change of the analog gainparameter, and (c) when the on/off state of the gain compensation of theaudio input port is set into the OFF state from the ON state by theapparatus, the switch selects the second switch contact for outputtingthe input digital audio signal from the AD converter.
 7. The apparatusaccording to claim 6, wherein the digital-amplifier is configured foradjusting the digital gain parameter by an amount different from thevalue change of the analog gain parameter.
 8. The apparatus according toclaim 6, wherein the switch is configured to perform, in accordance witha control signal from a remote device, the selecting of the first switchcontact or the selecting of the second switch contact.
 9. The apparatusaccording to claim 6, wherein the gain compensation is automatic. 10.The apparatus according to claim 6, wherein the digital-amplifier isconfigured for adjusting the digital gain parameter after the analoggain parameter is adjusted by the value change.
 11. The apparatusaccording to claim 6, wherein the apparatus is an IO device.
 12. Theapparatus according to claim 11, the IO device comprising the audioinput port and another of the audio input port.
 13. The apparatusaccording to claim 6, wherein the on/off state of the gain compensationis set into the ON state or the OFF state in accordance with a controlsignal from a remote device.
 14. The apparatus according to claim 13,wherein the audio input port is configured for operably coupling to aplurality of channels, wherein the on/off state of the gain compensationof the audio input port is common to all channels of the plurality ofchannels.
 15. The apparatus according to claim 6, wherein the apparatusis a device controlled by a control device, the control devicecomprising a console having a control panel which is provided thereonwith a plurality of controls for controlling the device.
 16. Theapparatus according to claim 6, wherein the apparatus is a devicecontrolled by a control device, the control device comprising a personalcomputer running thereon a control program for controlling the device.17. The apparatus according to claim 6, wherein the audio input port isoperably coupled to a first receiver of a first mixing device forreceiving a first input audio signal, the first input audio signal basedon the adjusted digital gain parameter, wherein the audio input port isoperably coupled to a second receiver of a second mixing device forreceiving a second input audio signal, the second input audio signalbased on the adjusted digital gain parameter, wherein, due to theadjusting, by the digital-amplifier, of the digital gain parameterinversely to the direction of the value change of the analog gainparameter, respective levels of the first input audio signal and thesecond input audio signal do not have to be respectively adjusted at thefirst mixing device and at the second mixing device inversely to thedirection of the value change of the analog gain parameter.
 18. Theapparatus according to claim 6, wherein the audio input port is operablycoupled to a first receiver of a first mixing device for receiving afirst input audio signal, the first input audio signal based on theadjusted digital gain parameter, wherein the audio input port isoperably coupled to a second receiver of a second mixing device forreceiving a second input audio signal, the second input audio signalbased on the adjusted digital gain parameter, wherein, due to theadjusting, by the digital-amplifier, of the digital gain parameterinversely to the direction of the value change of the analog gainparameter, respective levels of the first input audio signal and thesecond input audio signal do not change at the first mixing device andat the second mixing device.
 19. The apparatus according to claim 6,wherein the apparatus is one device among a plurality of devicesoperably coupled to an audio network, wherein the audio network iscapable of transporting a plurality of audio signals and at least onecontrol signal at the same time between the plurality of devicesoperably coupled to the audio network.
 20. The apparatus according toclaim 6, wherein the digital-amplifier is configured for adjusting thedigital gain parameter by the same amount as the value change of theanalog gain parameter.
 21. A method comprising: receiving, by an audioinput port, an input analog audio signal; controlling a level of theinput analog audio signal based on an analog gain parameter to output anoutput analog audio signal; converting the output analog audio signalinto an input digital audio signal; controlling a level of the inputdigital audio signal based on a digital gain parameter to output anoutput digital audio signal; wherein, (a) when an on/off state of gaincompensation of the audio input port is set into an ON state from an OFFstate, setting the digital gain parameter to a predetermined value andselecting a first switch contact for outputting the output digital audiosignal, (b) while the on/off state of the gain compensation of the audioinput port is in the ON state, adjusting the digital gain parameterinversely to a direction of a value change of the analog gain parameter,and (c) when the on/off state of the gain compensation of the audioinput port is set into the OFF state from the ON state, selecting asecond switch contact for outputting the input digital audio signal. 22.The method according to claim 21, wherein the digital gain parameter isadjusted by the same amount as the value change of the analog gainparameter.
 23. The method according to claim 21, wherein the digitalgain parameter is adjusted by an amount different from the value changeof the analog gain parameter.
 24. The method according to claim 22comprising: performing, in accordance with a control signal from aremote device, the selecting of the first switch contact or theselecting of the second switch contact.
 25. The method according toclaim 22, wherein the gain compensation is automatic.
 26. The methodaccording to claim 22, wherein the adjusting of the digital gainparameter is performed after the analog gain parameter is adjusted bythe value change.
 27. The method according to claim 22, wherein themethod is performed in an IO device.
 28. The method according to claim27, the IO device including the audio input port and another audio inputport, the method comprising: adjusting another digital gain parameter ofthe another audio input port inversely to another direction of anothervalue change of another analog gain parameter of the another audio inputport.
 29. The method according to claim 22, wherein the on/off state ofthe gain compensation is set into an ON state or an OFF state inaccordance with a control signal from a remote device.
 30. The methodaccording to claim 29, wherein the audio input port is configured foroperably coupling to a plurality of channels, wherein the on/off stateof the gain compensation of the audio input port is common to allchannels of the plurality of channels.
 31. The method according to claim22, wherein the audio input port is operably coupled to a first receiverof a first mixing device for receiving a first input audio signal, thefirst input audio signal based on the adjusted digital gain parameter,wherein the audio input port is operably coupled to a second receiver ofa second mixing device for receiving a second input audio signal, thesecond input audio signal based on the adjusted digital gain parameter,wherein, due to the adjusting of the digital gain parameter inversely tothe direction of the value change of the analog gain parameter,respective levels of the first input audio signal and the second inputaudio signal do not have to be respectively adjusted at the first mixingdevice and at the second mixing device inversely to the direction of thevalue change of the analog gain parameter.
 32. The method according toclaim 22, wherein the audio input port is operably coupled to a firstreceiver of a first mixing device for receiving a first input audiosignal, the first input audio signal based on the adjusted digital gainparameter, wherein the audio input port is operably coupled to a secondreceiver of a second mixing device for receiving a second input audiosignal, the second input audio signal based on the adjusted digital gainparameter, wherein, due to the adjusting of the digital gain parameterinversely to the direction of the value change in the analog gainparameter, respective levels of the first input audio signal and thesecond input audio signal do not change at the first mixing device andat the second mixing device.